HALF a million people with [...].
Retinal screening, which is carried out annually, tests for eye disease in diabetics known as diabetic retinopathy.
Diabetic retinopathy is the leading cause of blindness among the working-age population.
While the number of people at risk of blindness has dropped from around three-quarters of a million in 2008, the charity Diabetes UK says people are still not getting proper checks.
Those with the condition must ensure they are receiving 15 key services to help them keep healthy, it added.
In the UK, there are 2.8m people diagnosed with diabetes and an estimated 850,000 more have Type 2 diabetes but do not know it.
Almost a third of people with Type 1 diabetes and one in seven with Type 2 have not had a foot check. Diabetes causes 100 amputations a week, of which around 80% are thought to be preventable through proper foot health.
Barbara Young, chief executive at Diabetes UK, said: "Diabetes is a serious condition which can lead to devastating long-term complications including blindness, kidney failure and amputations.
"The tragedy is that, for example, 90% of cases of sight loss could have been avoided if they had been identified early enough and treated appropriately."